362 The American Geologist. December, iM)7 
nected somewhat brokenly witli a prominent level vallej' aver- 
aging a half mile in width, which follows quite closely the 
boundary line between sections 31 and 82 of the same town- 
ship. The northern third of this plain, viz., those portions 
lying in sections 19 and 20, lie at an elevation of from 1,020 
to 1,025 feet, and is almost level but somewhat depressed cen- 
trally. It drains northward to the St. Croix river. On the 
west this plain is limited abruptly by the river gorge which 
is a sharp descent of over 300 feet within a distance of less 
than half a mile. In most respects this level area resembles 
a terrace; it also reminds one of the similar development on 
the opposite side of the river, in Taylor's Falls, known as the 
picnic ground. But the difference in elevation of the tw-o is 
more than 100 feet, while the differences in character are 
equally striking. The St. Croix moraine forms its eastern 
boundary. Southward it is somewhat broken, but still it 
shows the same character, and near the south line of Sec. 29 
it is too much cut up to be recognized. From this southern 
portion of the plain a very prominent erosion valley leads 
toward the N. N. W., and follows its edge for nearly a mile 
to the railway station in St. Croix Falls. Southward still 
further, in Sees. 31 and 32, the plain again becomes prominent, 
this time, however, as a verj^ distinct valley lying between the 
St. Croix moraine on the east and the high diabase ridge on 
the west. This level tract narrows rapidly near the south line 
of Sec. 32, where it merges into a rook bound gorge. The 
walls of this gorge are precipitous on the west and rise grad- 
ually toward the east. The bed of the channel is solid igne- 
ous rock. This southern termination of the valley has an 
elevation of 1,010 feet. From this point southward another 
area is developed partly as a resultant of the first, but of very 
different character. All points necessary for decisive conclu- 
sions are not at hand. The only ones lending any weight 
toward conclusions as to origin are the following: The ma- 
terial is of eastern origin ; it slopes gradually toward the south 
and leads to a well marked late glacial river gorge; the west- 
ern boundary is in part the present river gorge which is, at 
this place, the limit of the western drift; the eastern bound- 
ai-y is at all times the St. Croix moraine which represents an 
eastern drift accumulation. 
